Automatically loadable and blade-stabilizing utility knife

ABSTRACT

An automatically loadable and blade-stabilizing utility knife including a handheld housing, a slidable pushing mechanism, a resilient section, a releasing mechanism and a receptacle section. The housing has an open front end and an open rear end and serves to accommodate several blades therein. The pushing mechanism serves to engage with and push one of the blades. The resilient section serves to push the blades. The releasing mechanism serves to release the blade from the pushing mechanism. The receptacle section is disposed in the housing between the front and rear ends. The overlapping blades are loaded into the receptacle section through the opening of the rear end. Only one of the blades is permitted to slide between the front and rear ends. A pair of guide rails are disposed in the housing. A slide block is disposed on the pushing mechanism between the guide rails, whereby the blade can be more stably loaded and used.

BACKGROUND OF THE INVENTION

The present invention is related to a knife as a hand tool, and moreparticularly to an automatically loadable and blade-stabilizing utilityknife.

The conventional utility knifes as hand tools have been developed byseveral stages.

The early utility knife has a housing composed of two substantiallysymmetrical casings locked together by screws. A blade is accommodatedin the housing. The housing has an opening at front end and is equippedwith a driving unit for pushing the blade to protrude from the front endand pulling the blade back into the housing. When the blade is worn out,a user must unscrew the screws to open the housing for changing thedirection of the blade or replacing the blade. It is troublesome and aptto get hurt to replace the blade.

An improved utility knife has a hooking unit disposed between the twocasings for easily opening the housing. However, a user still needs tochange the direction of the blade or replace the blade with hands.Therefore, the user is still easy to get hurt when replacing the blade.

A further improved utility knife has a switch disposed at the front endof the housing. By means of rotating or pressing the switch, the bladecan be extracted out of the housing to change the direction of the bladeor replace the blade. Then the blade is inserted into the front end ofthe housing. With such structure, it is unnecessary to open the housing.

According to the above structures, only one blade is received in thehousing. This is inconvenient in use. For example, in the case that nospare blade is available, it is impossible to further use the utilityknife. In some utility knifes, a spare blade is placed in the housing.However, it is still necessary for a user to open the housing andreplace the blade with hands.

Two kinds of advanced and automated utility knifes have been developed.Such utility knifes carry spare blades with themselves.

U.S. Pat. No. 5,604,984 discloses a first kind of utility knife carryingspare blade with itself. Such utility knife has a blade rest seatrotatable about a long axis of the housing. A series of blades arecircumferentially arranged in the blade rest seat. The utility knife isdesigned with several switches for replacing the blades inside thehousing. Such utility knife has some shortcomings as follows:

-   -   1. The structure of such utility knife is complicated. Also, it        is troublesome and uneasy to operate such utility knife. In        addition, the manufacturing cost for such utility knife is        relatively high.    -   2. The spherical blade rest seat leads to enlarged handle of the        utility knife. It is uneasy and uncomfortable to hold the        handle.    -   3. Referring to FIGS. 1A and 1B, the blade used in such utility        knife is not the one with standard commercial specification as        shown in FIG. 1A. Instead, the blade used in such utility knife        is a trapezoid one as shown in FIG. 1B. The angle contained        between the bottom side and the lateral side of the blade is        smaller than the standard specification so that the stress        strength of such blade is less. Especially when cutting a        caplet, the blade is very apt to break. Therefore, such utility        knife is not popular after released.

FIGS. 2 to 4 show the second kind of utility knife carrying spare bladewith itself. One side of the housing 91 is formed with a window 911. Acover 92 is pivotally latched in the window 911. Several overlappingblades 93 are transversely placed in the housing 91 through the window911. In the case that the utility knife drops down, the cover 92 is aptto bound away and the blades 93 may slip out of the window 911.Furthermore, with such structure, a user can hardly pinch two planefaces of the blades 93 with fingers to load the blades 93. Instead, theuser must pinch the sharp edges of the blades 93 to load the blades 93.Therefore, the fingers of the user are apt to be cut.

Moreover, after the blades 93 are placed into the housing 91, the blades93 are uneasy to tidily overlap each other and snugly attach to afeeding unit 94 disposed in the housing. Therefore, the feeding unit 94often fails to engage with the blade 93. This leads to malfunction ofthe utility knife.

On the other hand, the feeding unit 94 has an engaging block 941 forengaging with the blade. Two springs 942 are arranged on lateral sidesof the engaging block 941 for pushing the engaging block 941 to engagein the notches 931 of the blade 93. The utility knife serving as a handtool must be such designed that a user's hand can snugly hold the handleof the utility knife. Therefore, the housing 91 of the utility knife isfixed and thus the interior space of the housing 91 is limited.Accordingly, the two springs 942 are very small. It is uneasy toassemble so small components of the utility knife. In addition, once thesprings 942 are bent or inclined, the engaging block 941 cannoteffectively engage with the blade 93. This will lead to malfunction ofthe utility knife. Furthermore, when feeding the blade 93 to protrudefrom the front end of the housing 91, the blade 93 is simply engagedwith the engaging block 941 without any other design for stabilizing theblade 93. Therefore, the blade 93 can be hardly smoothly fed. Inaddition, the blade 93 is hung on the movable feeding unit 94. A gapmust exist between the feeding unit 94 and the housing 91 for easilymoving the feeding unit 94. As a result, the structure is unstable andwhen using the utility knife, the blade 93 is apt to swing.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide aknife. The blades can be easily, truly and safely loaded into thehousing of the knife.

It is a further object of the present invention to provide the aboveknife in which the blade can be more smoothly pushed and more reliablyused.

It is still a further object of the present invention to provide theabove knife which has simple structure and components for easily trulyengaging with the blade.

It is still a further object of the present invention to provide theabove knife which can be easily and firmly assembled to lower themanufacturing cost.

According to the above objects, the automatically loadable andblade-stabilizing utility knife includes a handheld housing, a slidablepushing mechanism, a resilient section, a releasing mechanism and areceptacle section. The housing has an open front end and an open rearend. The receptacle section is disposed in the housing between the frontand rear ends. A pair of guide rails are disposed in the housing. Aslide block is disposed on the pushing mechanism between the guiderails, whereby the blade can be more stably loaded and used.

The present invention can be best understood through the followingdescription and accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a front view of a blade of a conventional utility knife withstandard size;

FIG. 1B is a front view of a blade of a conventional utility knife withspecific size;

FIG. 2 is a perspective assembled view of a conventional utility knife;

FIG. 3 is a perspective exploded view of a conventional utility knife;

FIG. 4 is a front view of the conventional utility knife in whichoverlapping blades are loaded;

FIG. 5 is a perspective view of the utility knife of the presentinvention in which overlapping blades are loaded;

FIG. 6 is a perspective exploded view of the utility knife of thepresent invention;

FIG. 7 is a perspective exploded view of the utility knife of thepresent invention, seen in another direction;

FIG. 8 is a perspective view showing the interior receptacle section ofthe housing of the utility knife of the present invention;

FIG. 9 is a perspective according to FIG. 8, in which several blades areaccommodated in the receptacle section;

FIG. 10A is a side view of the housing in which the blades are loaded;

FIG. 10B is a sectional view taken along line I—I of FIG. 10A;

FIG. 11A is a front assembled view according to FIG. 5;

FIG. 11B is a top sectional view taken along line II—II of FIG. 11A,showing that the pushing mechanism of the present invention ispositioned in the first position;

FIG. 12A is a front assembled view according to FIG. 5;

FIG. 12B is a top sectional view taken along line II—II of FIG. 12A,showing that the pushing mechanism of the present invention ispositioned between the first and second positions;

FIG. 13A is a front assembled view according to FIG. 5; and

FIG. 13B is a top sectional view taken along line II—II of FIG. 13A,showing that the pushing mechanism of the present invention ispositioned in the second position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 5 to 13. The automatically loadable andblade-stabilizing utility knife 1 of the present invention includes ahandheld housing 11, a slidable pushing mechanism 12, a resilientsection 13, a releasing mechanism 14 and a receptacle section 15.

The housing 11 has a front end 111 and a rear end 112. Several blades113 can be accommodated in the housing 11. Each blade 113 has a notchedsection 113′. Each of the front and rear ends 111, 112 has an opening.The blades 113 are loaded into the housing through the opening of therear end 112. A restricting section 114 such as a leaf spring isdisposed at the rear end 112 for preventing the blades 113 from slippingout of the rear end 112.

The pushing mechanism 12 is disposed on the housing 11, including anactivating section 22 and a moving section 24.

The activating section 22 outward protrudes from the housing 11 and ismanually movable between the front end 111 and the rear end 112. Inaddition, the activating section 22 can be manually engaged with thehousing 11, whereby the pushing mechanism 12 can be fixed in a firstposition or a second position of the housing 11.

The moving section 24 is connected with the activating section 22 andpositioned inside the housing 11. When the pushing mechanism 12 ispositioned in the first position, the moving section 24 is adjacent tothe blades 113 for engaging with and pushing one of the blades 113 tothe second position and protruding the blade from the front end 111through the opening thereof.

The resilient section 13 is disposed on inner side of the housing 11.When the pushing mechanism 12 is positioned in the first position, theresilient section 13 serves to transversely push the blades 113 towardthe moving section 24.

The releasing mechanism 14 is transversely reciprocally movably disposedon the housing 11. When the pushing mechanism 12 is positioned in thesecond position, the releasing mechanism 14 serves to push the movingsection 24 to release the blade from the moving section 24. At thistime, the blade can be pulled out from the opening of the front end 111.

The receptacle section 15 is formed of two channels 151 having a certainlength in the lengthwise direction of the housing 11. The channels 151are spaced from the front end 111 and rear end 112 by a certain distanceand fixedly disposed in the housing 11. A partitioning body 52 isdisposed between a middle portion of the receptacle section 15 and thefront end 111 for partitioning the receptacle section 15 into a firstspace 54 and a second space 56. A distance between the inner sides ofthe bottoms of the channels 151 corresponds to the width of the blades113. The overlapping blades 113 are loaded through the opening of therear end 112 into the first space 54. Only one of the blades ispermitted to pass through the second space 56 and protrude from theopening of the front end 111.

The present invention further includes a first latch section 116, acover body 16 and a second latch section 62. The first latch section 116is disposed at the rear end 112. One end of the cover body 16 ispivotally connected with the rear end 112. The second latch section 62is disposed at the other end of the cover body 16. The first and secondlatch sections 116, 62 can be latched with each other forblocking/unblocking the opening of the rear end 112 of the housing 11.

In addition, the pushing mechanism 12 is further designed as follows:

A pair of guide rails 115 spaced from each other by a certain distanceare disposed in the housing 11 between the front end 111 and the rearend 112. A slide block 26 is disposed on the moving section 24.

The guide rail 115 has a transverse bent section 115′ between the firstand second positions of the housing 11. The bent section 115′ isobliquely bent toward the resilient section 13.

The slide block 26 is transversely slidably disposed on the movingsection 24 and positioned between the guide rails 115. The slide block26 has a sliding section 261 and an insertion section 262.

The sliding section 261 is disposed on two opposite sides of the slideblock 26 for abutting against the guide rails 115. After the slide block26 passes through the bent section 115′, the slide block 26 is displacedin a transverse direction of the housing 11.

The insertion section 262 is disposed on the slide block 26corresponding to the notched section 113′. When the slide block 26 isdisplaced, the insertion section 262 can be inserted into the notchedsection 113′ by different depths for engaging with one of the blades. Inother words, when the pushing mechanism 12 is positioned in the firstposition, the depth by which the insertion section 262 is inserted inthe notched section 113′ is not larger than the thickness of one blade.Therefore, the moving section 24 can only push one blade 113. After theslide block 26 moves forward toward the front end 111 and passes throughthe bent section 115′, the slide block 26 is biased to make theinsertion section 262 inserted in the notched section 113′ by a largerdepth which is even larger than the thickness of one blade 113. Thismakes the slide block 26 more firmly engaged with the blade so that theutility knife can be more reliably used.

According to the above arrangement, the utility knife of the presentinvention has the following advantages:

-   -   1. Referring to FIG. 5, the overlapping blades are loaded into        the housing from the opening of the rear end 112 by way of        insertion. A user can conveniently, easily and safely pinch the        blades with fingers. This meets the requirement of engineering        of human body.    -   2. Referring to FIGS. 8 and 9, the receptacle section 15 for        accommodating the blades 113 is formed of two channels 151        having a certain length in the lengthwise direction of the        housing 11. The channels 151 are spaced from each other by a        certain distance and fixedly disposed in the housing 11. The        receptacle section 15 has a form of a cartridge. This is        different from the conventional structure on which the blades        are hung. Therefore, the blade can be more smoothly pushed and        more reliably used.    -   3. The bent section 115′ of the guide rail 115 serves to guide        and displace the slide block 26. After the slide block 26 moves        forward toward the front end 111 and passes through the bent        section 115′, the slide block 26 is biased to make the insertion        section 262 inserted in the notched section 113′ by a larger        depth which is even larger than the thickness of one blade 113.        This makes the slide block 26 more firmly engaged with the blade        so that the utility knife can be more reliably used.    -   4. The slide block 26 is slidably engaged with the blade. Such        simple structure and component can easily truly engage with the        blade. In contrast, the conventional structure employs small        springs which can hardly achieve reliable engagement.    -   5. The present invention can be easily and firmly assembled to        lower the manufacturing cost. Especially, the slide block 26 is        firmly assembled with the moving section 24 by way of insertion.

In the above structure of the present invention, the pushing mechanism12 further includes a first abutting section 241 and a second abuttingsection 242.

The first abutting section 241 extends from the moving section 24 towardthe rear end 112 and the blades 113 by a certain length. The firstabutting section 241 abuts against the rear edge of a blade closest tothe first abutting section 241 to aid the moving section 24 in pushingand driving the blade.

The second abutting section 242 extends from the first abutting section241 toward the rear end 112 by a certain length. When the pushingmechanism 12 is positioned in the second position, the second abuttingsection 242 serves to abut against one side of a blade next to thedriven blade. Therefore, the pushing mechanism 12 can be moved back tothe first position without obstruction.

The above embodiments are only used to illustrate the present invention,not intended to limit the scope thereof. Many modifications of the aboveembodiments can be made without departing from the spirit of the presentinvention.

1. A knife comprising: a handheld housing having a front end and a rearend, the housing serving to accommodate several blades therein, eachblade having a notched section, the front end having an opening; aslidable pushing mechanism disposed on the housing and including anactivating section and a moving section, the activating section outwardprotruding from the housing and being manually movable between the frontend and the rear end, the activating section being manually engageablewith the housing, whereby the pushing mechanism can be fixed in a firstposition or a second position of the housing, the moving section beingconnected with the activating section and positioned inside the housing,whereby when the pushing mechanism is positioned in the first position,the moving section is adjacent to the blades for engaging with thenotched section and pushing one of the blades to the second position andprotruding the blade from the front end through the opening thereof; aresilient section disposed on inner side of the housing, whereby whenthe pushing mechanism is positioned in the first position, the resilientsection serves to transversely push the blades toward the movingsection; and a releasing mechanism transversely reciprocally movablydisposed on the housing, when the pushing mechanism is positioned in thesecond position, the releasing mechanism serving to push the movingsection to release the blade from the moving section, whereby the bladecan be pulled out from the opening of the front end, said knife beingcharacterized in that a pair of guide rails spaced from each other by acertain distance are disposed in the housing between the front end andthe rear end, a slide block being disposed on the moving section; eachguide rail has a transverse bent section between the first and secondpositions of the housing, the bent section being obliquely bent towardthe resilient section; the slide block is transversely slidably disposedon the moving section and positioned between the guide rails, the slideblock having a sliding section and an insertion section; the slidingsection is disposed on two opposite sides of the slide block forabutting against the guide rails, whereby after the slide block passesthrough the bent section, the slide block is displaced in a transversedirection of the housing; and the insertion section is disposed on theslide block corresponding to the notched section, whereby when the slideblock is displaced, the insertion section is inserted into the notchedsection by different depths for engaging with one of the blades.
 2. Theknife as claimed in claim 1, wherein the pushing mechanism furtherincludes a first abutting section and a second abutting section, thefirst abutting section extending from the moving section toward the rearend and the blades by a certain length, the first abutting sectionabutting against a rear edge of a blade closest to the first abuttingsection to aid the moving section in pushing and driving the blade, thesecond abutting section extending from the first abutting section towardthe rear end by a certain length, whereby when the pushing mechanism ispositioned in the second position, the second abutting section serves toabut against one side of a blade next to the driven blade so as to movethe pushing mechanism back to the first position without obstruction.